Urgent : Extension xS10 toasted after firmware upgrade ?

I just upgraded my M203 (fwspi) without any problems, but xS10 won't come up after upgrade with fwserial.
I received some Flashing errors on the cli during the upgrade (timeout & invalid data), and after that the unit was unresponsive.
Since I did this form work, I restarted the unit when I came home (after more than one hour). Before I had 4 LEDs lit up permanently: PWR (red), RUN, RX and TX.
After reboot only PWR is lit permanently (red).

Does this mean my unit is toast ? Can this be fixed in a timely manner ? Half of our house is now without lights...

pro-side : Really fast answer from unipi; I like this kind of good customer service !

Down-side I am wondering (and also replied on the e-mail):

Isn't there any error-checking on the firmware upgrades ? is this technically possible ? Or a fall-back switch to revert to previous firmware ?

Sending the unit in snail mail and waiting for repair is a lengthy process, especially when half of the house is in the dark and there is no other option to switch the lights. Maybe temporary replacement parts could be handy ? Maybe from local resellers ?

For the people who encounter the same problem or just stumble on this post by coincidence:

UniPi tech wrote: “We know the firmware update, especially of the extensions, is a sort of Achilles heel and we are thinking about some concept of dual firmware to which you can revert to if the flashing of the new firmware fails.”

I also would like to mention the excellent support from UniPi! I’ve received a very fast and meaningful response from both the technical as commercial team, and they are moving heaven and earth to provide me the fastest possible solution.

I didn’t experience such a personal approach from an international company since a long time.